1. Field of the Invention
This invention relates generally to an apparatus for recording and/or reproducing at least video signal information on a record sheet, and more particularly is directed to a recording and/or reproducing apparatus of the type in which signal transducers are mounted for rotation in a circular path transverse to the direction of movement of the record sheet, whereby such video signal information is recorded on and/or reproduced from the sheet in a series of parallel record tracks.
2. Description of the Prior Art
Conventional apparatus for recording and/or reproducing video signals, that is, a video tape recorder (hereinafter referred to as VTR), has employed a magnetically coated recording tape which is wound on at least one reel and which is transported from such reel in a helical path about the circular path of rotation of magnetic heads or transducers so that the latter record and/or reproduce video signal information in parallel record tracks extending obliquely across the tape. However, the reel or reels having the tape wound thereon are bulky and relatively heavy, and thus are inconvenient for transportation and storage thereof. Further, when it is desired to record or reproduce signals on a portion of the tape intermediate its ends, it is necessary to either unwind or rewind the tape on the supply reel in order to gain access to the desired portion of the tape, and such unwinding or rewinding is time consuming. If such wasted time is to be reduced, for example, by providing fast forward and rewind operating modes, the apparatus becomes undesirably complicated. The described existing apparatus is also disadvantageous in that special operations are required for still- or slow-motion reproduction.
The existing VTR employing magnetic tape as the recording medium, as described above, requires a highly accurate servo system for ensuring that the transducers accurately scan the record tracks during recording and/or reproducing operations. In cases where the magnetic tape is contained in a cassette, relatively complex mechanisms are required for withdrawing the tape from the cassette housing and training the withdrawn tape about the usual guide drum associated with the rotary heads or transducers. Finally, in the case of video signals recorded on magnetic tape, as aforesaid, the mass reproduction of the recorded tape is difficult and expensive.
It has been proposed, for example, in U.S. Pat. No. 2,915,596, issued Dec. 1, 1959, to record and/or reproduce intelligence or information on a sheet of paramagnetic material in an apparatus that comprises a cabinet provided with an interiorly directed, semi-cylindrical guide channel into which the sheet is insertable in the direction of curvature of the channel so as to engage a straight margin of the sheet with an abutment extending parallel to the longitudinal axis of the semi-cylindrical channel for guiding the sheet in its slidable movement within the channel parallel to that axis by means of a rotated drive roller extendable into the channel. Rotary magnetic transducers or heads are moved in a circular path that substantially coincides with the curvature of the channel for recording or reproducing signals on the sheet therein, with the slidable movement of the sheet and the rotary movement of the transducers combining to cause the transducers to scan spaced-apart, parallel record tracks on a portion of the sheet. The foregoing arrangement is disclosed specifically only for the magnetic recording and reproducing of sound and is suitable, if at all, only for that purpose. If an attempt is made to employ the apparatus disclosed in U.S. Pat. No. 2,915,596 for recording and/or reproducing video signal information, the spaced apart relation of the successive record tracks and the consequent poor utilization of the sheet area for the recording of signal information results in a relatively short playing time for each sheet. Further, the existing apparatus, as aforesaid, is incapable of simultaneously recording and/or reproducing both video signal information and associated audio signal information. It is also apparent that the sheets employed individually as the recording medium in the existing apparatus have their para-magnetic coatings exposed to damage when not in use, particularly after recording, and futher that such sheets are susceptible to creasing when not in use or when being inserted into the apparatus, particularly if formed of desirably thin film material.
It has also been proposed, for example, as in German patent appplication No. P 21 43 382.9, filed Aug. 26, 1971, and No. P 21 50 524.8, filed Oct. 6, 1971, to record video signal information on a record disc which is normally contained in a protective cover or envelope and which, in the recording and/or reproducing apparatus, is fully removed from the cover or envelope and displaced to an operative position where the disc is rotated about its center while being scanned by a transducer or head in a spiral track. The foregoing arrangement is undesirable in that difficulties are experienced in returning the disc to the protective cover or envelope at the completion of a recording or reproducing operation, and further in that the conditions necessary for high fidelity recording and reproducing of video and audio signals are not realized. Further, the last proposed arrangement provides an undesirably short playing time for the recording or reproducing of the video signals.